As computing technology has advanced, computing devices such as smart phones, tablet computers, desktop computers, and so forth have become increasingly commonplace. Users often times desire to restrict access to their devices, whether because they don't want others to use the functionality that the devices provide, because they store data on their devices that they desire to keep secret, or some other reason. To restrict access, devices typically have an authentication step that must be passed by the user before they can access one of their devices, such as entry of a password or personal identification number (PIN) on a log-in screen, or capturing of a fingerprint by a dedicated fingerprint sensor. Such authentication steps, however, can be time consuming and detract from the usability of the devices, leading to frustrating user experiences.